The present invention relates to a compressor and, more particularly, to a rotary compressor for compressing refrigerant, suitable for use in air conditioners for automobilies wherein the pressure angle and the side thrust formed between the vane and the rotor almost comes to 0.degree. so as to save the driving power and to increase compression efficiency of the compressor.
According to the conventional rotary compressor, whatever the outer peripheral surface or rotor, the center line of the gas-blocking vanes are mostly aligned with the center of the rotor, which usually causes a large pressure angle which is formed between the centerline of the vane and the normal line of the contacting curved surface of both the vane and the rotor when the rotor rotates. The pressure angle usually causes an undesired side thrust between the vane and the inner wall of its guiding slot. The side thrust generates heat, not only to shortening the life of the vane but also to wasting the driving power and to lowering the efficiency of the compressor. Therefore, it is generally in considered desirable to prevent the pressure angle from attaining over 30.degree. in designing a compressor. Nevertheless, it is inevitable that a pressure angle between the vane and the rotor for compressor or engine be formed.
For example, the hydraulic servo-mechanism of U.K. Pat. No. 1,394,138 provides for a pressure angle of about 45.degree.; the balanced rotary combustion engline of U.S. Pat. No. 3,797,464 provides for a pressure angle of about 37.degree.; and the rotary compressor with vanes in housing and suction through the rotor of U.S. Pat. No. 4,345,886 provides for pressure angle of about 27.degree.. In other words, the current rotary compressors all provide for a relatively large pressure angle between vanes and the rotor, which cause an undesirable side thrust.
Therefore, an object of the present invention is to provide a novel rotary compressor which forms a non-pressure angle during the performance of the compression duty.
Another object of the present invention is to provide a novel rotary compressor which has a revolution speed of about 100 to 300 RPM to work as efficiently as a high revolution compressor, and consequently the compressor in accordance with the present invention may be driven by a low voltage DC motor, especially suitable for the automobile compressor.
Still another object of the present invention is to provide a novel compressor which is adaptable to be driven by a DC low-voltage DC motor, whereby, its compression efficiency will be constant without being influenced by the off-and-on of an automobile's traveling conditions.
A further object of the present invention is to provide a novel compressor which saves 33% of the driving power in comparison with the equivalent currently existing compressor.
This and other objects of the invention will become clear from the following description of the preferred embodiment taken in conjunction with the accompanying drawings as well as from the appended claims.